Tea bags and filters with variable porosity and custom steeping cycles

ABSTRACT

A container that controls combining a soluble material with a solution includes a body that holds the soluble material and a film that covers the body and having pores therein, where flow through the pores is impeded after a pre-determined amount of time following the soluble material in the container being combined with the solution outside the container. The soluble material may be tea. The solution may be water. The body may have a frame that supports the film. The pores may contract to impede flow therethrough. The pores may contract in response to temperature of the solution, in response to a pH level of a combination of the solution and the soluble material. and/or in response to being exposed to water. The container may include beads disposed proximal to the pores, where the beads expand to impede flow through the pores.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Prov. App. No. 62/509,347, filed on May 22, 2017, and entitled “TEA BAGS AND FILTERS WITH VARIABLE POROSITY AND CUSTOM STEEPING CYCLES”, which is incorporated herein by reference.

TECHNICAL FIELD

This application is directed to the field of food packets with filtering properties, and more particularly to tea bags and filters with variable porosity for adaptive tea brewing.

BACKGROUND OF THE INVENTION

Tea is the most popular brewed beverage on the planet and is second only to drinking water among world's liquid refreshments. The tea market represents 6% or nearly $11 billion in consumer dollars spent in food service beverage category in 2014. Between 2010 and 2015, tea saw a 16% increase in menu occurrences. Within the 10-year period, 2006-2015, global tea production has grown from 3.5 to 5.2 million metric tons and, according to industry forecasts, is expected to grow faster through the next decade. In particular, an outlook for black tea production is at 2.9% annual increase, reaching 4.17 million metric tons by 2023. The size of the global tea beverage market in 2013-2021 is estimated to grow from 34.9 billion to 44.3 billion US dollars.

In each of the top 24 countries with highest per capita tea consumption, an average person consumes annually over 1 kg (35.3 oz.) of tea. While the US holds only 70th place in annual per capita tea consumption, the beverage can be found in 80% of US households, and on any given day, over 158 million Americans, that is, over 50% of the US population, are drinking tea. The South and the Northwest represent two regions with the greatest concentration of tea drinkers. Among diverse age groups, US millennials are most likely to drink tea at 87%, compared with the 80% average for all US consumers. Both tea consumption and tea import have grown in the US in 2015 (US is the world's third largest tea importer).

The consumption of hot tea has been growing steadily over the 2010-2015 period, as consumers embrace its health benefits, which range from maintaining proper fluid balance and antioxidant properties to reducing risks of certain cancers, neurological decline and osteoporosis and playing a positive role in an overall metabolism. Total category sales for hot tea have increased more than 15% over the last 5 years. The structure of tea consumption in the US is characteristic for the Western world: 85% is black tea, 14% is green tea and the small remaining amount is split between oolong, white and dark tea.

In 2015, more than 69% of hot tea purchased in the U.S. was bagged tea. Herbal teas were at about 30% and loose teas made up about 1% of purchases. The dynamics of consumption, however, gives the preference to loose tea, which continues to grow in both dollars and units sold and shows a trend to enjoy maximum benefits from quality teas.

Proper steeping of hot tea plays an important role in consumer satisfaction with the beverage. A characteristic of a successful steeping process are the right tea, the right water, the right water temperature and the right steep time. Different tea varieties have a broad range of optimal steep times, ranging from one to three minutes for white teas to two-three minutes for most green teas, three-to-five minutes for black teas and five-to-seven minutes for many herbal teas. Over-steeping teas of most varieties is not, generally speaking, considered unhealthy and is sometimes intentionally done by certain consumers and in some cultures. However, a common result of over-steeping is a bitter taste due to excessive release of tannins, which is undesirable for many tea lovers and leads to loss of ideal taste for delicate tea varieties.

Since hundreds of millions of people use bagged teas in busy office and work environments and have no time to read specific steeping instructions on tea bags or cans of loose tea or to carefully control steeping time even if known, both knowing the right moment to pull out the tea bag from a cup and avoiding over-steeping tea become problematic and negatively affect the tea culture.

Accordingly, it would be useful to have a mechanism to control the steeping process to eliminate over-steeping of freshly-brewed tea and indicate to consumers when a cup of tea is fully steeped and ready for drinking.

SUMMARY OF THE INVENTION

According to the system described herein, a container that controls combining a soluble material with a solution includes a body that holds the soluble material and a film that covers the body and having pores therein, where flow through the pores is impeded after a pre-determined amount of time following the solution being combined with the soluble material in the container. The soluble material may be tea. The solution may be water. The body may have a frame that supports the film. The pores may contract to impede flow therethrough. The pores may contract in response to temperature of the solution, in response to a pH level of a combination of the solution and the soluble material. and/or in response to being exposed to water. The container may include beads disposed proximal to the pores, where the beads expand to impede flow through the pores. The beads may expand in response to temperature of the solution, in response to a pH level of a combination of the solution and the soluble material, and/or in response to being exposed to water. The container may also include an indicator, coupled to the container, that indicates when flow through the pores is impeded. The indicator may change color in response to the pores being impeded. The indicator may measure pH of a combination of the solution and the soluble material. The amount of time may vary according to density of the pores per unit area of the film, size of the pores, and/or material used for the film. The soluble material may be tea and the solution may be hot water and the amount of time may be used to control a strength of a beverage that results from combining the tea and the hot water. The soluble material may be tea and the solution may be hot water and the container may be a bag that holds the tea. The container may include an indicator, coupled to the bag, that indicates when steeping of the tea is complete.

The proposed system offers a tea stick as a replacement for a tea bag and a modified construction of a tea filter for loose tea, whereby a body of the stick or a pocket of the filter is made of a material or constructed in a way that provides varying porosity, so that the pores are gradually closed (gradually contract) as steeping progresses, following various physical and/or chemical characteristics of the partially brewed tea, so that contact between tea leaves inside the bag or filter and the freshly brewed tea outside the bag/filter is cut off once the tea is fully steeped. A steeping cycle may be customized for various tea varieties. Additionally, a handle of the tea stick or a portion of the filter bag outside the cup may have an indicator (such as an indicator strip) that changes color at an end of the steeping cycle under influence of capillary absorption of brewed tea, thus displaying to a consumer readiness of the tea for drinking.

The body of the tea stick, partially or completely submerged into hot water at a start of steeping, may have several alternative constructions securing varying porosity of the body and custom steeping cycle:

-   -   A surface of the body portion of the stick may be made of a         water-resistant plastic film made of a polymer which gradually         changes volume either (1) on reaction with water, (2) at         elevated temperature (above 60 Celsius or so), (3) in response         to pH change, or (4) a combination of the above. The film may         have nanopores to allow for the passage of water and dissolved         tea components (tannins, alkaloids, colloidal cellulose, etc.).         The surface may be optionally mounted on a light metallic,         plastic or other internal frame. Chemical properties of the         polymer may ensure that a surface of the film expands under an         influence of kinetic characteristics and/or pH value produced by         the steeping process, which leads to gradual closure of the         pores. The pores may be fully open on initial immersion in hot         water, thus allowing the brewing process to take place, but as         the volume of the plastic changes, the pores may gradually close         over a period of several minutes, stopping further brewing after         a desired time has elapsed. The size and density of artificial         pores are tuned to particular values of the above         characteristics or pH, so that full closure of the pores and         isolation of the body from exterior water (to prevent further         steeping) comes precisely at an end of an ideal steeping cycle         for a particular variety of tea leaves that partially fill the         body of the tea stick.     -   Instead of self-closing pores, the surface may be made of a         neutral non-stretching polymer or other film and pores may have         constant size through the steeping process.     -   The custom steeping cycle is instead achieved by adding a         polymeric bead hanging in (fastened to) each pore and possessing         the above-mentioned property to expand under an influence of         chemical parameters and/or temperature of the steeping process         to impede flow through the pores. Similarly to the first         construction, the enlarged beads may protrude from the pores at         the end of the steeping cycle and close the interior of the tea         stick submerged in the water.

Empty filter pockets for loose tea may also have one or both of the above constructions.

It may also be possible to vary both the initial permeability of the film (by varying the density of pores per unit area) and the pore closure time (by varying the pore size and, to some extent, the material properties) to adjust a strength of the tea to consumer preferences. In other words, it may be feasible to have, for one and the same variety of tea, sticks for bagged tea and filters for loose tea that may be corresponding to weak tea, regular tea, and strong tea and marked accordingly.

Additionally, a strip or other geometric configuration made from an indicator that changes color when certain chemical characteristics of the aqueous solution reach a values of fully steeped tea (for example, a pH value for the fully steeped condition of a particular variety of tea) may be mounted inside or on a surface of a handle of a tea stick or on an outside portion of an empty tea filter pocket. A small absorbing portion of the strip or other material attached to the strip may protrude inside the body or the pocket to take advantage of capillary absorption of the tea and to change color at a time of completion of the steeping process, letting the user know that the tea is ready for drinking.

Indicators may be further customized to show readiness for different tea strengths.

There exist polymers such as alginate, PMA, PMEP, PMAETMA, and PNIPA whose volume changes as a function of pH and/or temperature. It may be possible to adjust a threshold pH at which polymer volume change occurs, and a magnitude of the volume change, by adding, removing, or protecting (derivatizing so as to make unreactive) pH-sensitive functional groups (amino groups or carboxylic acid groups, depending on the polymer) on the chain ends and/or side chains—the more pH-sensitive groups are present, the earlier (closer to neutral pH) the volume change occurs, and the greater (within limits) the magnitude of the change.

Also, it may be possible to adjust the rate of the volume change by cross-linking the polymer in such a way that the cross-links will gradually hydrolyze at elevated temperature and/or due to a change in pH (for example, with ester and/or hydrazone cross-links)—the more cross-links and the more resistant the cross-links are to hydrolysis, the slower the volume change takes place, and the later (farther from neutral pH) volume change begins (if the cross-links hydrolyze due to pH change).

Additionally, there exist acid-base indicators such as cyanidin-3-glucoside which change color at an approximate pH of brewed tea and which are non-toxic and safe for use in food products.

The material for tea sticks and filters should be food grade and, ideally, biodegradable.

Other potential applications of the system described herein may include unified sticks for soluble medicine that may provide different strengths of the medicine in one stick depending on the conditions, such as an initial water temperature and, for example, a presence of a small amount of salt or soda in water. In this case, multiple indicators may be provided to distinctively color code different strengths of the solution.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the system described herein will now be explained in more detail in accordance with the figures of the drawings, which are briefly described as follows.

FIG.s 1A-1B are schematic illustrations of assembled tea sticks and tea filters with custom steeping cycles, according to an embodiment of the system described herein.

FIG.s 2A-2B are schematic illustrations of two different constructions of the surface of a tea stick or a tea filter, according to an embodiment of the system described herein.

FIG. 3 is a schematic illustration of the customized steeping process, according to an embodiment of the system described herein.

FIG. 4 is a system flow diagram illustrating system functioning in connection with a customized and controlled tea steeping process, according to an embodiment of the system described herein.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

The system described herein provides a tea stick as a replacement for a tea bag and a modified construction of a tea filter for loose tea and methods of control of steeping process, along with indicators of readiness of the fully steeped tea for consumption.

FIGS. 1A-1B are schematic illustrations of assembled tea sticks and tea filters with custom steeping cycles.

FIG. 1A is a schematic illustration of an assembled tea stick 110, which may include two principal parts: a body 120 and a handle 125. The body 120 is covered with a polymer film 130 with an optional frame 135 and has pores 140, representing openings in the body 120 of the stick 110, allowing hot water to enter the body 120 and contact loose tea leaves 150 placed at a bottom of the body 120. The handle 125 may have an indicator element or strip 160 that changes color at an end of a steeping cycle under the influence of capillary absorption of brewed tea, as explained elsewhere herein.

FIG. 1B schematically illustrates a modified tea filter 170. Here, loose tea leaves 150′ are poured into a pocket 180 to form a layer 155 at a bottom of the pocket 180. A plurality of pores 140′ play the same role as the pores 140 for the tea stick 110, while an indicator strip 190 may be attached to a back side of the pocket 180.

FIGS. 2A-2B are schematic illustrations of two different constructions of a surface of a tea stick or a tea filter.

FIG. 2A illustrates self-closing pores 210 made in the surface 130, gradually closing (contracting) during steeping, as explained elsewhere herein, to impede flow through the pores 210.

FIG. 2B illustrates constant-size pores 220 in the surface 130 with polymeric beads 230 hanging in or fastened to each of the pores 220 optionally using a thin frame 240. The beads 230 expand during steeping, as explained elsewhere herein, to impede flow through the pores 220.

FIG. 3 is a schematic illustration 300 of a customized steeping process using the tea stick 110 with self-closing pores 140, showing three phases of the steeping process. Initially, the tea stick 110 with the pores 140 fully opened is placed into a cup 310, either already filled with hot water 320 or with the hot water 320 is added when the stick is already in the cup 310. The hot water 320 has an initial pH value 325 corresponding to a start of the steeping process. The hot water 320 flows through the pores 140 into the body of the stick 110, contacts loose tea leaves 150 at the bottom of the stick 110 and flows back into the cup 310, as depicted by arrows 330.

At an intermediate phase of the steeping process, the pores 140 start to contract, as illustrated by smaller openings 340 in the pores 140; a resulting semi-brewed tea 350 has an intermediate pH value 355 and flow of liquid through the partly closed pores 340 is less intense than initial flow through the pores 140.

Finally, fully brewed tea 360 with a final pH value 365 corresponds to fully closed pores 370. A flow of liquid inside the stick is impeded and an indicator element 380 changes color to signal to the user that the tea is ready.

Referring to FIG. 4, a system flow diagram 400 illustrates system functioning in connection with a customized and controlled tea steeping process. Processing begins at a step 410, where it is determined whether a tea stick is used, like the tea stick 110, described above. If not, processing proceeds to a step 420, where loose tea leaves are added to a tea filter like the tea filter 170, described above. After the step 420, processing proceeds to a step 430, where the tea filter is placed into a tea cup. After the step 430, processing proceeds to a step 450, where hot water is poured into the tea cup.

If it was determined at the test step 410 that a tea stick was used, processing proceeds from the step 410 to a step 440, where the tea stick is put into the tea cup. After the step 440, processing proceeds to the step 450, described above, where hot water is poured into the tea cup. The step 450 can be independently reached from the step 430. After the step 450, processing proceeds to a step 460, where tea steeping progresses, pores are gradually closing (or beads expanding) and steeping intensity declines, as explained elsewhere herein. After the step 460, processing proceeds to a test step 470, where it is determined whether the tea is fully steeped. If not, processing proceeds back to the step 460. Otherwise, if the tea is fully steeped, processing proceeds to a step 480, where flow through the pores is impeded and steeping stops, as explained elsewhere herein (for example, at the final phase, depicted in FIG. 3). After the step 480, processing proceeds to a step 490 where the indicator strip or other element changes color and notifies the user that the tea is ready. After the step 490, processing is complete.

Note that the system described herein may be adapted to control an amount of time any soluble material is mixed with a solution. The soluble material may be medicine, coffee, other consumable food or drink, non-consumable soluble material, etc. Also, the solution may be a liquid other than water, including non-consumable liquids. The system described herein relies on the addition of the solution to cause flow through pores in the surface of the container to eventually be impeded based on a characteristic of the solution (e.g., temperature) or on a characteristic of the combination (e.g., pH of the combination).

Various embodiments discussed herein may be combined with each other in appropriate combinations in connection with the system described herein. Additionally, in some instances, the order of steps in the flowcharts, flow diagrams and/or described flow processing may be modified, where appropriate. Subsequently, system configurations and decisions may vary from the illustrations presented herein. Various existing and future materials may be used for the surface of tea sticks and tea filters, beads, indicator strips and other system components.

Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims. 

What is claimed is:
 1. A container that controls combining a soluble material with a solution, comprising: a body that holds the soluble material; and a film that covers the body and having pores therein, wherein flow through the pores is impeded after a pre-determined amount of time following the solution being combined with the soluble material in the container.
 2. A container, according to claim 1, wherein the soluble material is tea.
 3. A container, according to claim 2, wherein the solution is water.
 4. A container, according to claim 1, wherein the body has a frame that supports the film.
 5. A container, according to claim 1, wherein the pores contract to impede flow therethrough.
 6. A container, according to claim 5, wherein the pores contract in response to temperature of the solution.
 7. A container, according to claim 5, wherein the pores contract in response to a pH level of a combination of the solution and the soluble material.
 8. A container, according to claim 5, wherein the pores contract in response to being exposed to water.
 9. A container, according to claim 1, further comprising: beads disposed proximal to the pores, wherein the beads expand to impede flow through the pores.
 10. A container, according to claim 9, wherein the beads expand in response to temperature of the solution.
 11. A container, according to claim 9, wherein the beads expand in response to a pH level of a combination of the solution and the soluble material.
 12. A container, according to claim 9, wherein the beads expand in response to being exposed to water.
 13. A container, according to claim 1, further comprising: an indicator, coupled to the container, that indicates when flow through the pores is impeded.
 14. A container, according to claim 13, wherein the indicator changes color in response to the pores being impeded.
 15. A container, according to claim 14, wherein the indicator measures pH of a combination of the solution and the soluble material.
 16. A container, according to claim 1, wherein the amount of time varies according to at least one of: density of the pores per unit area of the film, size of the pores, or material used for the film.
 17. A container, according to claim 16, wherein the soluble material is tea and the solution is hot water and wherein the amount of time is used to control a strength of a beverage that results from combining the tea and the hot water.
 18. A container, according to claim 1, wherein the soluble material is tea and the solution is hot water and wherein the container is a bag that holds the tea.
 19. A container, according to claim 18, further comprising: an indicator, coupled to the bag, that indicates when steeping of the tea is complete. 